Associated Factors for Hyponatremia in patients with Sellar Lesions

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 130-162-Neuroendocrinology
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-139
Marcia Gabriela Jimenez*, Javier Mauricio Farias, Ana Paula Lisdero, Karina Miragaya, Miguel Walter Vasquez Cayoja, Cecilia Goldaracena, Maria Cecilia Paszkiewicz and Marina Khoury
Sanatorio GŁemes, Buenos Aires, Argentina
Normotonic hyponatremia may be related with sellar Lesions (SL) as described in several series(1). This reports showed association between severe hyponatremia and macroadenomas(2) or empty sella syndrome in elderly population(3).

Objectives:  To describe the hyponatremia frequency in patients with SL and to analyze differences in lesion size, age and adrenal and thyroid status.

Patients and Methods:  We retrospectively reviewed the clinical records of 108 patients with sellar lesions who consulted in our endocrinology unit from  January 2011 to December 2012. Fifty-eight patients with SL whose natremia had been measured at the time of diagnosis were included. Age, gender, lesion size, adrenal and thyroid status were evaluated. 

We divided all patients in two groups by age: 1) 16 to 65 and 2) more than 65-years old; and in three different groups by size: a) macroadenoma, b) microadenoma and c) empty sella. Hyponatremia was defined by a plasma sodium level less than 135 mEq/l, adrenal insufficiency by a morning plasmatic cortisol less than 10 ug/dl and hypothyroidism by a Free-T4 serum level less than 0,93ug/dl.

Chi-square tests were used to compare the distribution difference of categorical variables. A binary logistic regression analyses was performed to evaluate predictive variables of hyponatremia.

Results: Median age was 47 years (range 16-89), 70% were female, 16 of 58 patients had empty sella syndrome (27,5%) Median serum sodium was 137mEq/l (range 115-147 mEq/l) and hyponatremia frequency was 17.2% (10/58).

On univariate analysis, three independent variables increased the risk of hyponatremia: age more than 65 (OR 16.5 p=0.001), adrenal insufficiency (OR 5.133 p=0.031) and empty sella (OR 5.7 p=0.018). Gender and thyroid status were not predictive variables.

On multivariate analysis, age more than 65 years old (OR 8.437 p=0.02) and empty sella (OR 6.204 p=0.046) remained significant but low serum cortisol level did not show a significant statistic association (OR 3.75 p=0.172).

Conclusion: We suggest, that both patients, over 65 years old and those suffering from an empty sella had an increased risk of hyponatremia in this series. Low serum cortisol level might be another predictive variable but a major sample size should be required.

(1) Duong H et al., Endocr Rev 2012; 33 (03_Meeting Abstracts):MON 727. (2)Shigeru N et al., Neurol Med Chir 2000; 40:249. (3) Kurtulmus N et al., Aging Clin Exp Res 2006; 18:536.

Nothing to Disclose: MGJ, JMF, APL, KM, MWV, CG, MCP, MK

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm